Electric machine output shaft

Abstract

The present invention relates to a connecting system for an output shaft (21) of an electric machine with a transmission system, the connecting system being formed by a connecting element (3) mounted on an output shaft (21), the output shaft (21) comprising a knurling (22). Abstract figure: Figure 1

Description

Title of the invention: Output shaft of an electric machine

[0001] The present invention relates to the field of mobility devices, in particular motor vehicles, and more specifically aims at an output shaft of an electric machine for an electric propulsion system allowing the transmission of power to drive wheels of such devices.

[0002] The electric propulsion system allowing the transmission of power in a motor vehicle, aims to rotate at least one wheel of the vehicle, by transmitting the torque supplied by a drive shaft, in particular electric or hybrid.

[0003] Such a system comprises an electric machine formed by at least one electric motor, an electronic assembly, and a reducer for transmitting the torque.

[0004] The engine output shaft is used for the transmission connection, for example by belt.

[0005] The belt is thus configured to transmit the engine torque to at least one drive wheel of the vehicle, in particular to two drive wheels of the vehicle. A disadvantage in these systems today comes from the fact that the output shaft interface is not adaptable to all types of belt or other transmission element.

[0006] The present invention therefore aims to overcome one or more of the drawbacks of the systems of the prior art by proposing a connecting element for an output shaft making it possible to adapt the shaft to any type of transmission element.

[0007] For this purpose, the present invention proposes a connection system, for an output shaft of an electric machine, with a transmission system, the connection system being formed by a connection element mounted on an output shaft, the output shaft comprising knurling.

[0008] According to one embodiment of the invention, the connecting element is formed by a ring comprising grooves or teeth.

[0009] According to one embodiment of the invention, the ring (31) has an internal face (33) with a hardness lower than that of the grooves (32) or teeth (32).

[0010] According to one embodiment of the invention, the connecting element (3) is held in place on the shaft (21) by a holding element (34).

[0011] According to one embodiment of the invention, the internal face (33) is treated thermochemically or by quenching.

[0012] According to one embodiment of the invention, the thermochemical treatment is cementation, carbonitriding or nitriding.

[0013] According to one embodiment of the invention, the quenching is carried out after surface heating by induction, flame, laser, electronic bombardment.

[0014] The invention also relates to an electric machine for a mobility device. comprising a connection system (10) according to the invention.

[0015] The invention also relates to the use of the electric machine according to the invention in a propulsion system for a mobility device.

[0016] The invention also relates to a mobility device, comprising a coupling system according to the invention.

[0017] Other aims, characteristics and advantages of the invention will be better understood and will appear more clearly on reading the description given below, with reference to the appended figures, given by way of example and in which:

[0018] [Fig-1]: [Fig.l] is an elevation view of part of a tree with a system connecting according to one embodiment of the invention,

[0019] [Fig.2]: [Fig.2] is an elevation view of part of the connection system according to an embodiment of the invention,

[0020] [Fig.3]: [Fig.3] is an elevation view of part of a tree with part of the connection system according to one embodiment of the invention.

[0021] The invention relates to a connection system for an output shaft of an electric machine. The electric machine is a machine of a propulsion system for a mobility device. The present invention is aimed in particular at use in a motor vehicle but also at use in any land, air or sea vehicle, intended for the transport of passengers or goods, light, intermediate or heavy, or even construction machinery or agricultural machinery.

[0022] In the context of the invention, a propulsion system is a system which allows propulsion and comprises the elements allowing the transmission of power from the engine to the wheel.

[0023] The electric machine comprises at least one electric motor, an electronic assembly, and a reducer for transmitting the torque.

[0024] According to an embodiment of the invention visible [Fig.l], the motor 2 is an electric motor.

[0025] The electric motor 2 via the reducer thus makes it possible to drive at least one rotating wheel. The reducer allows the application of a reduction ratio to the motor: it will reduce the output speed of the motor while increasing the torque to adapt to the operating requirements.

[0026] According to one embodiment of the invention, the coupling, via the motor shaft, between the motor 2 and the reducer is achieved with a belt.

[0027] In the context of the invention, the connection between the output shaft of the electric motor 2 and the belt is achieved by a connection system 10.

[0028] According to one embodiment of the invention, the connecting system 10 is formed by a connecting element 3, visible [Fig.2], mounted on a shaft 21 comprising a knurling 22, visible [Fig.3]. The connecting element 3 is formed by a ring 31 comprising 32 splines or 32 teeth. These 32 splines or teeth allow torque to be transmitted via a belt.

[0029] According to one embodiment of the invention, the connecting element is held in place on the shaft 21 by a nut-type holding element 34.

[0030] In the context of the invention, the internal face 33 of the ring 31, that is to say the interface zone with the shaft 21, has a hardness lower than that of the splines 32 or teeth so that the material can deform for a better interface. Whereas the splines 32 or teeth must be able to withstand contact pressures with another gear. For example, the interface zone with the shaft has a hardness equal to 18HRC and the splines 32 or teeth have a hardness equal to 59 HRC.

[0031] According to one embodiment of the invention, the interface zone 33 is treated thermo-chemically or by quenching, that is to say by a surface hardening treatment aimed at hardening the surface of the material.

[0032] According to one embodiment of the invention, the thermochemical treatment which makes it possible to modify the chemical composition of the surface is, for example, cementation, carbonitriding, nitriding.

[0033] According to one embodiment of the invention, the quenching is carried out after surface heating by induction, flame, laser, electronic bombardment.

[0034] Such a system makes it possible, with the same drive shaft, to adapt different types of transmission means, such as different belts, only by changing the connecting part 3.

[0035] An electric machine comprising such a connection system can be used in a mobility device with 2, 3, 4 or more wheels. And for example, a motor vehicle or a motorcycle, in propulsion, alternator-starter or hybrid mode.

[0036] The scope of the present invention is not limited to the details given above and allows embodiments in many other specific forms without departing from the scope of the invention. Therefore, the present embodiments should be considered by way of illustration, and may be modified without departing from the scope defined by the claims.

Claims

Claims

1. Connection system (10), for an output shaft (21) of an electric machine, with a transmission system, the connection system being formed by a connection element (3) mounted on an output shaft (21), the output shaft (21) comprising a knurling (22).

2. Connecting system (10) according to claim 1, in which the connecting element (3) is formed by a ring (31) comprising grooves (32) or teeth (32).

3. A connecting system (10) according to claim 1 or 2, wherein the ring (31) has an internal face (33) with a hardness lower than that of the grooves (32) or teeth (32).

4. Connecting system (10) according to one of claims 1 to 3, in which the connecting element (3) is held in place on the shaft (21) by a holding element (34).

5. Connection system (10) according to one of claims 1 to 4, in which the internal face (33) is treated thermochemically or by quenching.

6. A bonding system (10) according to claim 5, wherein the thermochemical treatment is carburizing, carbonitriding or nitriding.

7. Bonding system (10) according to claim 5, in which the hardening is carried out after surface heating by induction, flame, laser, electronic bombardment.

8. Electric machine for a mobility device comprising a connection system (10) according to one of claims 1 to 7.

9. Use of the electric machine according to claim 8 in a propulsion system for a mobility device.

10. Mobility device, comprising a coupling system according to one of claims 1 to 7.

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